Visibility The greatest distance that prominent objects can be seen and identified by unaided, normal eyes.
Visibility is measured by scattering of light. Either some light is transmitted, and the device measures how much is received a distance away, or the scattered portion is measured directly.
Visibility is also used in water, as a measure of turbidity.
visibility - 1. The greatest distance in a given direction at which it is just possible to see and identify with the unaided eye 1) in the daytime, a prominent dark object against the sky at the horizon, and 2) at night, a known, ...
VISIBILITY A measure of the opacity of the atmosphere, and therefore, the greatest distance one can see prominent objects with normal eyesight. The National Weather Service has various terms for visibility.
Visibility - the greatest distance toward the horizon that prominent objects can be identified visually with the naked eye
Visible Radiation - the type of electromagnetic radiation that the human eye can detect ...
Visibility Protection Program
The program specified by the Clean Air Act to achieve a national goal of remedying existing impairments to visibility and preventing future visibility impairment throughout the United States.
Visibility The greatest distance an observer can see and identify prominent objects.
VISIBILITY: The greatest distance at which it is possible with the unaided eye to recognize a prominent dark object against the horizon sky.
Visibility: The maximum horizontal distance at which objects can be identified.
Visible radiation: Electromagnetic radiation with wavelengths between approximately .4 to .7 microns. Human vision occurs at these wavelengths.
Visibility
The greatest distance an observer can see and identify prominent objects.
Visible light
That portion of the electromagnetic spectrum from 0.4 to 0.7 µm wavelengths that is visible.
visibility—The greatest distance one can see and identify prominent objects.
visual range—See runway visual range.
vortex—In meteorology, any rotary flow in the atmosphere.
Visibility- The greatest horizontal distance an observer can see and identify a prominent object.
Sector Visibility The visibility in a specific direction that represents at least a 45° arc of a horizontal circle.
oblique visibility"Same as oblique visual range.
oblique visual range"(Also called oblique visibility, slant visibility.) The greatest distance at which a specified target can be perceived when viewed along a line of sight inclined to the ...
Visibility: Largest distance in which an object of defined characteristics can be seen and identified with naked eye.
Visibility- The greatest distance at which one can see and identify objects.
Virga- Water droplets or ice crystals that fall from high clouds but that evaporate before hitting the ground.
Visibility: the distance at which a given standard object can be seen and identified with the unaided eye.
Visibility - The greatest distance that is possible for a person to see with their eyes. When fog occurs, a persons visibility is lowered.
Surface Visibility: Surface visibility determined at a defined location.
Sun: My Article. Sunspot: Storms on the Sun of electrified gases reach maximum about every 11 years. SW- Designated letter for light snow showers.
PREVAILING VISIBILITY It is considered representative of visibility conditions at the observation station. It is the greatest distance that can be seen throughout at least half the horizon circle, but not necessarily continuous.
Prevailing Visibility: The visibility that is considered representative of conditions at the station; the greatest distance that can be seen throughout at least half the horizon circle, not necessarily continuous.
Exceptional Visibility
Visibility such that objects are readily visible at a great distance.
Visibile or VisibilityVisibilityThe distance at which a given standard object can be seen and identified with the unaided eyeVisibility Protection ProgramThe program specified by the Clean Air Act to achieve a national goal of remedying ...
Runway visibility The visibility along an identified runway, determined from a specified point on the runway with the observer facing in the same direction as a pilot using the runway. Compare to runway visible range.
Similar to fog, but visibility remains more than a kilometre.
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MJO ...
BlizzardIncludes winter storm conditions of sustained winds or frequent gusts of 35 mph or more that cause major blowing and drifting of snow, reducing visibility to less than one-quarter mile for 3 or more hours.
In observing, sand is reported when particles of sand are raised to sufficient height that reduces visibility. It is reported as "SA" in an observation and on the METAR. SANDSTORM A strong wind carrying sand particles through the air.
Now, it means air that has restricted visibility due to pollution or pollution formed in the presence of sunlight--photochemical smog.
Fog is often hazardous when the visibility is reduced to ¼ mile or less.
Improvement in visibility cannot be expected until the rain stops or moves out of the affected area.
This can sometimes be inferred by a change in humidity (it should 'feel' more humid), and there may be a line of precursor cumulus development, with a change in visibility and wind direction perhaps.
There is now one operating at the MSP airport, reporting air temperature, cloud ceiling, visibility, dew point, and wind among other things. Forecasters use the frequent ASOS reports to refine and update forecasts.
Visibility generally between 400 and 1000 m.
Snow: Large numerous flakes and visibility generally between 400-1000 m.
Hail: particles numerous enough to whiten the ground.
Heavy: ...
Hazard Warning: Restricted visibility.
Advection fog often looks like Radiation Fog and is also the result of condensation.
It is characterized by low temperatures, strong winds and poor visibility due to blowing snow. True blizzard conditions are most common on the prairies of Canada and the United States.
Individually these are not visible but cumulatively they will diminish visibility.heatA form of energy transferred between systems by virtue of their temperature differences.
The chaser has to cope with at least flooding, slick roads, and zero visibility. In more severe storms, there can be strong winds, lightning, and large hail. The chaser can easily lose a windshield if he or she penetrates a hail producing storm core.
BLIZZARD A severe weather condition characterized by low temperatures, winds 35 mph or greater, and sufficient falling and/or blowing snow in the air to frequently reduce visibility to 1/4 mile or less for a duration of at least 3 hours.
storm with strong winds, the technical definition for a blizzard requires: at least 3 hours in duration; low temperatures (usually less than minus 7C or 20F), strong winds (greater than 55 km/h or 35 mph), blowing snow which reduces visibility to ...
It is usually used at night to describe less than 3/8 opaque clouds, no precipitation, no extremes of visibility, temperature or winds. It describes generally pleasant weather conditions.
This is how some multicell cluster storms will appear as they approach, again assuming good visibility. The ominous shelf cloud, appearing like a mustache with this storm, is the leading edge of the storm outflow.
Blowing Dust- dust that is raised by the wind to moderate heights above the ground to a degree that horizontal visibility decreases to less than seven miles.
Blowing Snow- wind blown snow that reduces horizontal visibility.
Blowing Snow- Blowing snow is wind-driven snow that reduces surface visibility.Blowing snow can be falling snow or snow that has already accumulated but is picked up and blown by strong winds. Blowing snow is usually accompanied by drifting snow.
BLOWING SNOW: Wind-driven snow that reduces visibility near the ground. Blowing snow can be either falling snow or snow that has already accumulated but is picked up and moved by strong winds.
Fog - A cloud, with its base on the surface, reducing visibility. If visibility is frequently reduced to 1/4 of a mile or less, the fog is termed dense fog.
A cloud with its base at the earth's surface. It reduces visibility to below 1 km.
Forced convection(6)
On a small scale, a form of mechanical stirring taking place when twisting eddies of air are able to mix.
CONTROLLED AIRSPACE - An area of airspace which may be subject to air traffic control. Visibility and cloud clearance requirements are higher in controlled airspace, regardless of whether communications with ATC are required or not.
A dense mass of small water droplets suspended in the air near the ground. Visibility is reduced to less than 1 kilometre. See also Radiation fog, Advection Fog, Upslope fog and Mist.
Forced convection ...
Mist Very thin fog in which visibility is greater than 1.0 km (0.62 mi).
Mixing ratio Mass of water vapor per mass of dry air; expressed as grams per kilogram.
Haze - a mixture of particles in the air reducing visibility.
Humidity - relative humidity, usually. A way of expressing moisture content in the air.
Fog - condensed water vapor or a cloud floating close to the ground and likely to obscure visibility.
Force - Push or pull that gives energy to an object, sometimes causing a change in the motion of the object.
BLIZZARD- Snow with winds greater than 35 mph and visibility of 1/4 mile or less that lasts for several hours.
BLO- Below.
Minute water droplets suspended in the air that reduce surface visibility to less than 1000m. Fog is cloud on the ground.
Freak waves ...
A resource as identified by the Federal Land Manager for one or more federal areas, that may be adversely affected by a change in air quality. The resource may include visibility or a specific scenic, cultural, physical, biological, ecological, ...
Smog Originally smog meant a mixture of smoke and fog. Today, smog means air that has restricted visibility due to pollution, or pollution formed in the presence of sunlight - photochemical smog.
duststorm: when strong winds blow over a dusty area, blowing the dust into the air and reducing visibility significantly.
The term reflects the danger involved in observing such an area visually, which must be done at close range in low visibility.
Ground clutter may hide or confuse precipitation echoes near the radar antenna.
Gunge - [Slang], anything in the atmosphere that restricts visibility for storm spotting, such as fog, haze, precipitation (steady rain or drizzle), ...
The color of light has no effect on visibility in fog; no color "penetrates" fog better than any other, but some colors may give improved contrast.
This area often coincides with a radar hook echo and/or mesocyclone, especially one associated with an HP storm. The term reflects the danger involved in observing such an area visually, which must be done at close range in low visibility.<> ...
 See also: Air, Weather, Surface, Cloud, Temperature
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